SMUD’s Fleet Goes ‘Green’

While technology has made many industries “cleaner and greener,” the utility industry has concentrated its activities in becoming cleaner mostly in the generation area.

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While technology has made many industries “cleaner and greener,” the utility industry has concentrated its activities in becoming cleaner mostly in the generation area. Electric utilities in particular have been getting away from coal and incorporating more natural gas while also trying to increase the amount of renewable energy in their portfolios. One area commonly overlooked where any utility can become cleaner is in its fleet operations.

At the Sacramento Municipal Utility District (SMUD) they have been taking major steps for more than 20 years to make their utility as clean as it can be with an increasing amount of renewable energy resources from solar to wind to methane recovery from dairy cows, as well as other technologies. Over roughly that same time period, they have also taken huge strides in cleaning up their vehicle fleet operations. There are three main areas they have concentrated on:

  1. Electric and hybrid vehicles
  2. Alternative liquid fuels
  3. Cleaner internal combustion engines

Electric Vehicles, Plug-in Hybrids and Fuel Cell Vehicles

For about 20 years, SMUD has been testing numerous clean, alternative-fuel vehicles, mostly electrics, in an effort to help manufacturers bring those vehicles to the market. They started with full battery electric vehicles, many of which the company still owns and operates. Then they moved on to hybrids, plug-in hybrids and even hydrogen fuel cell vehicles. They use these lighter duty vehicles for everything from meter reading to routine utility business. SMUD is now concentrating on plug-in hybrids in support of major national initiatives to bring these vehicles to market.

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One of the Prius plug-in hybrids
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The plug-ins SMUD has been testing and using, a couple of Prius conversion vehicles, can achieve 100 miles per gallon and up to about 1000 miles per tank of gasoline under normal commute driving. Simply plug in the car to a standard 110-volt outlet (preferably overnight) and the car is ready to do a lot of driving with little attention to refueling and significantly reduced emissions. While conventional hybrid cars use a gasoline-powered engine to charge a battery-powered electric motor to drive the vehicle, the plug-in hybrid combines conventional gas-electric hybrid technology with a larger battery that allows the car to rely on electric “boost” more of the time.

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One of the five Ford Focus hydrogen vehicles
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Regarding fuel cell vehicles, this spring SMUD partnered with BP, Ford and the US Department of Energy to open a hydrogen fuel cell vehicle fueling station that is powered by an 80-kilowatt solar panel array. The array produces enough hydrogen for about 14 hydrogen fuel cell vehicles (FCVs). As the solar panels make electricity, an electrolyzer at the station will use that energy to separate water into hydrogen to make clean fuel for the vehicles. They have been testing seven FCVs for three years now. Since the station is connected to the SMUD grid, the solar panel array can also produce enough power for about 40 single-family homes.

Heavy Duty Fleet Is Also Going Green

SMUD is also a pioneer in “green” fleet vehicle operations and they are using hybrid technology for some of their heavy duty work trucks. SMUD has just purchased a hybrid 60-foot aerial lift bucket truck to do large-scale electrical distribution system repair and maintenance. SMUD has four more of these trucks on order, with delivery expected by the end of the year. These trucks will share duty with other diesel trucks SMUD owns, but don’t get the impression the hybrid bucket truck is the only “clean” vehicle like it in their fleet. Over the past five years, SMUD has retrofitted 40 of its heavy-duty diesel trucks with emission reducing catalyst exhaust traps. SMUD also began using cleaner ultra-low sulfur diesel fuel in its diesel fleet several years before it was mandated.

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One of the two Daimler hydrogen vehicles
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With new light duty hybrid vehicles becoming available on the market it has become easier for SMUD to meet its goal of replacing conventional light duty vehicles with hybrids. This has allowed SMUD to place 36 hybrids into normal fleet operations.

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SMUD’s solar-powered hydrogen fuel cell vehicle fueling station
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SMUD also operates a fleet of propane vehicles, including pickups, forklifts and lawn mowers. SMUD has a biodiesel pilot program in place. Additionally, there is a strong push to replace all gasoline and diesel vehicles that are operated on the main campus with zero emission Neighborhood Electric Vehicles (NEVs).

In early 2005, SMUD began fueling 28 fleet vehicles with 85 percent ethanol fuel (E85). The E85 mixture is a renewable fuel source as the ethanol portion is derived mainly from corn and in the future will use cellulosic waste products. Since 2005, SMUD’s E85 fleet has grown to more than 70 vehicles. The on-premises fueling site, which is operated under an experimental permit with the California Air Resources Board (CARB,) is one of only five such sites in California.

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As a result of all these fleet programs, SMUD has reduced average fleet emission reduction of 7 percent per year in 2006 and 2007 and is expecting an additional 10 percent reduction in 2008.

The Garage is Clean Too

On the maintenance side, SMUD’s fleet is using re-refined motor oil in its vehicles. SMUD also has an oil-testing program that has reduced motor oil consumption in heavy duty vehicles by 37,000 quarts and has eliminated the disposal of approximately 1,000 oil filters over the past 30 months. They have also implemented a heavy truck air cleaner recycling program, where filters are washed, cleaned and tested. This program significantly reduces the number of air filters that are sent out for disposal. One more thing: SMUD is also switching over its fleet to inherently biodegradable hydraulic oil in an effort to reduce the environmental impact that can occur in the event of a hydraulic system failure or spill.

SMUD’s environmental fleet programs have been recognized with state of California “Clean Shop” certifications as an environmentally friendly operation.

Why all the extra effort to be so clean? It’s part of the core values at SMUD. The company is a ratepayer-owned electric utility and their customers, through the election of their board of directors, have demanded that they be a clean and environmentally friendly utility. It’s also just good business.

For more information about SMUD’s clean air efforts, If you are interested in getting more information feel free to e-mail: or

About the Author: Brian Smith is superintendent of Transportation at SMUD. Bill Boyce is Supervisor of the SMUD Electric Transportation program.

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